Benat Intxausti of Spain, riding for the Movistar team, won the stage, a 238km ride from the French resort of Valloire, in 5hr 52 min.

Intxausti beat Estonian Tanel Kangert in a sprint finish, with Nibali and his rivals in the general classification, Australian Cadel Evans and Colombian Rigoberto Uran, coming in as part of the same peloton 14sec behind.

Evans stands 1min 26sec off Nibali, with Uran 2.46 off the Italian's pace.

"You might have thought the stage would be easy, but it wasn't the case," Nibali said.

"A lot of riders from Monday's day off. The Giro, the Tour, they're raced like that. In the final descent, I didn't try to gain time, I only sought to control. It's been a good day, I can only be happy."

The big loser of the day's racing was Mauro Santambrogio. The Vini Fantini rider started in fourth overall but lost more than two minutes.

"Over three weeks, a bad day can happen to anyone," said Santambrogio in reference to Bradley Wiggins and Michele Scarponi. "Today was my turn. Tomorrow, I'll ride out calmly with the goal of doing well at each occasion that presents itself. Even if it didn't happen today as I had hoped, I can't complain about my Giro."

A 22-rider breakaway formed several times in the ascent of the Mont-Cenis mountain frontier between France and Italy. Nibali and his team were content to hand them a lead that once stretched to almost five minutes.

But they were eventually reeled back in with 20km to race, with Astana taking up the lead.

Evans and Uran reeled in Nibali's group 11.5km from the finish after the Italian had gone on the attack down a spectacular descent that featured a series of hairpin turns.

Kangert then attacked and at the 6km mark took with him Intxausti, Lampre's Polish rider Przemyslaw Niemiec and Dutchman Robert Gesink, who was later knocked out of the equation with a flat tire.

Intxausti, competing in the Giro for a third time, took his moment perfectly for the a first-ever stage win on a Grand Tour.

"It wasn't an easy sprint. At 3km, Kangert got on my wheel and I knew he was my opponent," said the 27-year-old Intxausti. "At 700 meters, I was able to keep my head and stay in the saddle, and at 300 meters, with a tailwind, I attacked on the outside."

The 17th stage on Wednesday sees the riders tackle a 214km course between Caravaggio and Vincenza.